The present invention is directed generally to couplings for fluid conduits and more particularly to a dry break apparatus for coupling together and uncoupling a pair of fluid conduits with no loss of fluid therefrom.
Dry break valve couplings are known in the art but certain problems remain unresolved with such known couplings. First, the known couplings do provide leakage of up to a teaspoon or more of fluid when the coupling is engaged and disengaged. Although the fluid loss may be insignificant, the damage done by such leakage may be quite significant when hazardous materials are being handled such as certain fertilizers in agricultural applications. Leakage is generally caused by the fact that the fluid flow between the housings of the couplings contacts the joint between the housings, thereby leaving a residue on the housing end portions upon disconnection. The same problem occurs at the joint or engagement surfaces of the piston and poppet within the respective housings.
Another problem with known dry bleak couplings is that the poppet and piston valve elements of the respective housings cannot be locked in their closed positions when the housings are disengaged. Accordingly, both housings are susceptible to accidental opening of the valve therein which may result in the spillage of hazardous material onto adjacent persons or surroundings.
Finally, a serious problem with known dry break fluid couplings is that the connection between the housings of all couplings of one manufacturer are uniform so that one housing of a given coupling may be alternately connected to the opposite housing of any similar coupling. Accordingly, the supply hose of a tank truck intended for handling a certain fluid may be accidentally coupled to the valve housing on a storage tank for a different fluid. Thus the result may be either the transfer of the wrong fluid or the loss of fluid due to mixing of incompatible fluids.
The above-described problems are resolved by the dry break coupling of the present invention.